VINCI (“Volume Imaging in Neurological Research”) was designed for the visualization and analysis of volume data generated by medical tomography systems with special emphasis on the needs for brain imaging with Positron Emission Tomography (PET). CPS Inc. (now Siemens Medical Solutions) acquired a license to ship previous versions of VINCI with their PET systems, and it is the standard visualization tool for the HRRT brain scanner. VINCI version 4.x, is a new line of development. VINCI is highly modular, extensible, compact and runs well on a wide range of systems; it can run directly off a CD-ROM or USB stick: no installation is required. This was achieved with a plugin architecture; VINCI can be remotely controlled through several high-level language interfaces, at the basis of which is Vinci’s XML-based scripting language. Fully automatic registration for many routine uses is also possible, including online feedback of a running registration. VINCI supports a number of file formats for reading (e.g. DICOM, NIfTI, ECAT7, MicroPET, Analyze, HRRT image, Bruker Paravision, Interfile) image files.